Is Coconut Oil All It's Cracked Up To Be? Get The Facts On This Faddish Fat

In the past few years, coconut oil has been called a superfood that can help you blast belly fat and raise your good cholesterol. The sweet and nutty trendsetter has been featured in many cookbooks as a substitute for olive or canola oil — and it can cost a bundle at the store.

A recent survey found that 72 percent of Americans say coconut oil is a "healthy food," but many nutrition experts aren't convinced.

The problem is that coconut oil contains a lot of saturated fat — the kind that is a big risk factor for heart disease, which kills more than 17 million people a year worldwide.

First, let's talk about fat. "In terms of calories, all fats are the same: butter, coconut oil, olive oil. They all have the same number of calories, but they are different in terms of your health," says Mary Donkersloot, a Beverly Hills nutritionist and host of a weekly Web video series called The Smart Eating Show.

Fat is not the enemy of our diets, despite what we were led to believe in the 1990s, when low-fat cookies and ice cream started popping up on the market. (Remember the SnackWell's craze?) Fat helps us feel full longer and stay satisfied. Eating some fat can actually help us snack less and potentially lose weight. But what kind of fat we eat matters — and how much.

In fact, one tablespoon of coconut oil has 12 grams of saturated fat — a big chunk of what is recommended for the whole day, says Donkersloot.

The U.S. government recommends keeping saturated fat below 10 percent of your total daily calories. For some people, that can be as low as 22 grams a day, although the American Heart Association recommends going even lower — more like 13 grams. So just one tablespoon of coconut oil gets you much of the way there. Forget dessert!

The concern about too much saturated fat in our diets is upheld by 50 years of research showing that a diet high in saturated fat is associated with an increased risk of heart attack and stroke, says Alice Lichtenstein, a professor of nutrition science and policy at the Friedman School at Tufts University who also runs the university's Cardiovascular Nutrition Laboratory.

Lichtenstein and her colleagues looked at several studies examining what happens when people replaced saturated fats found in foods like tropical oils and meat with unsaturated fats like those in olive oil, canola oil and flaxseed oil. As they reported in a recent American Heart Association advisory, those studies showed that making the swap was linked with a 30 percent reduction in the risk of cardiovascular disease. That's similar to what people can expect when they take statins, she says. The advisory was published in the journal Circulation.

So why does the idea that coconut oil is somehow good for us persist? No one is really sure.

"Why things like coconut oil somehow slipped under the radar is a little bit unclear, but it's not consistent with any of the recommendations that have occurred over the past 30, 40, 50 years," says Lichtenstein.

While some research has linked the main type of saturated fatty acid in coconut oil — lauric acid — to increased levels of HDL, or "good" cholesterol, it still raises LDL cholesterol, or "bad" cholesterol, she notes in the advisory, citing multiple studies.

And while enthusiasts point out that coconut oil is rich in antioxidants, there is little evidence that once the oil is refined, which is how most of us buy it in the store, those properties are retained.

Some research suggesting that saturated fat might be more neutral than previously thought has caused a few to question the American Heart Association and the government's recommendations on saturated fat.

But Lichtenstein and many others are not convinced. She says those studies did not take into account the kinds of foods replacing saturated fats in the diet, and that the saturated fat factor trumps the potential benefits of coconut oil.

So, if you like to cook with coconut oil, that's fine — "once in a while. If you're making Thai, go for it," says Donkersloot.

But don't think of coconut oil as a health elixir. And remember that when it comes to good nutrition, including fats, it's all about balance, Lichtenstein says. And there's more solid evidence behind the healthfulness of other plant-based oils such as extra virgin olive oil.

With the rise in popularity of low-carb diets embracing more fat in recent years, it's no wonder consumers are confused about which fats are best. And most oils contain more than one variety of fat. Iowa State University has a handy chart to help you compare the percentages of fats found in common oils.

Copyright 2018 NPR. To see more, visit https://www.npr.org.